10 peasants killed in Colombia massacre

A drug-trafficking paramilitary group has killed 10 peasants on a farm in northern Colombia in the country's worst massacre in more than three years.

Three gunmen from a group known as Los Rastrojos, The Scraps, stormed the farm in Antioquia state on Wednesday and apparently demanded an extortion payment.

General Humberto Guatibonza, commander of the police anti-kidnapping unit, said on Thursday authorities believed the Rastrojos killed the nine men and one woman when they didn't pay the money.

He said a dozen detectives were investigating the crime.

The owner of the farm in the municipality of Santa Rosa de Osos, about 275 kilometres northeast of the capital of Bogota, was apparently being extorted by the paramilitary group, local officials said.

Antioquia police General David Guzman said the gunmen arrived when the workers were finishing up their day of picking fruit.

When workers said they didn't know anything about an extortion payment, the gunmen opened fire and tossed a grenade at them.

"This case has shocked us for the barbaric, brutal way that they murdered these completely innocent people," Guzman said.

An Associated Press photographer who saw the 10 bodies being removed from the farm said the white walls of the main house were pock-marked by bullets and the floor was splattered with blood.

At least 150 farm labourers gathered at the main square in Santa Rosa de Osos fearing new attacks, he said.

It was the first major massacre in Colombia since August 2009, when 12 members of the Awa indigenous tribe were killed in southwestern Narino state.

At the time, a prosecutor investigating the case said the killings had been committed by Los Rastrojos.

The group is a violent offshoot of the Norte del Valle cartel involved in drug trafficking, extortion and murder as it competes with other criminal bands that grew out of the far-right militias known as paramilitaries.

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